Nitrocellulose propellants have been made and used many years. These propellants have generally utilized from about 10 to 60% weight percent of nitrocellulose as the binder. A characteristic of nitrocellulose propellants is their tendency to undergo degradation after storage. With the best known stabilizers to date, nitrocellulose propellants degrade when stored higher than 122.degree. F.
Nitrocellulose has been utilized in crosslinked nitrocellulose propellants. A method of processing of crosslinked nitrocellulose propellants to prevent gassing of the propellant is disclosed in my U.S. Pat. No. 3,711,344 assigned to the United States of America as represented by the Secretary of the Army. The nitrocellulose content of the propellant composition produced by the disclosed process ranged from about 5 to about 25 weight percent of the propellant composition.
Nitrocellulose has also been utilized with hydroxy-terminated polybutadiene as the binder. My U.S. Pat. No. 3,726,729 assigned to the United States of America as represented by the Secretary of the Army discloses propellant compositions which utilizes nitrocellulose in amounts from about 5 to 40 weight percent and hydroxy-teminated polybutadiene in amounts from about 1 to about 15 weight percent. These propellants were smoky propellants containing aluminum and ammonium perchlorate.
The combination of a nitrocellulose binder with an explosive nitrate ester plasticizer such as nitroglycerin is designated "double-base propellant composition". When high energy and oxidizer materials such as powdered aluminum and ammonium perchlorate are also included in a double-base composition, the composition is then designated "composite double-base propellant composition". A problem associated with the double-base or composite double-base propellant has been the attainment of proper thermal stability in the higher temperature range. Thus the actual "high-temperature thermal stability" has been evaluated by means of a standard 120.degree. C. deflagration test wherein the sample is held at 120.degree. C. until deflagration, or self ignition at a constant temperature, occurs. The testing results are reported in time to deflagration at 120.degree. C., minutes The typical valves of the control and the test propellant compositions, as illustrated in column 5 of U.S. Pat. No. 3,726,729 vary from about 550 to about 600 minutes for the control propellant containing nitrocellulose as the binder to over 2,000 when hydroxy-terminated polybutadiene is included as part of the binder for the composition.